JP5966806B2 - Fixing member, fixing device, and image forming apparatus - Google Patents

Description

  The present invention relates to a fixing member, a fixing device, and an image forming apparatus.

In an image forming apparatus such as a copying machine or a printer using an electrophotographic system, an image is formed by fixing a mi-fixed toner image formed on a recording sheet by a fixing device.
The fixing device includes, for example, a configuration including a heating roll and a pressure belt arranged in contact with the heating roll, or a pressure roll arranged in contact with the heating belt and the heating belt. There is known a fixing device called a belt nip system having a configuration.

For example, Patent Document 1 discloses that “a roller used for fixing a toner image transferred onto a transfer material, wherein the roller is formed by laminating an elastic layer, an intermediate layer, and a release layer on a cored bar. In a fixing roller using a low hardness rubber for an elastic layer and increasing the deformation rate of the elastic layer, the intermediate layer is composed of a wrinkle prevention layer made of high strength rubber and an adhesive / buffer layer thereon. A fixing roller is disclosed.
Patent Document 2 states that “the hardness when only the elastic layer is formed on the core metal is different between the fixing roller and the pressure roller, and the roller whose hardness is low when only the elastic layer is formed on the core metal. A fixing device in which the product hardness of the roller is higher than the product hardness of a roller having a high hardness when only the elastic layer is formed on the core metal is disclosed.
Patent Document 3 states that “an elastic layer formed on the surface of a base material, a release layer formed as an uppermost layer, and a release layer between the elastic layer and the release layer, A fixing belt in which an intermediate layer having a high tensile elastic modulus is formed is disclosed.
Further, Patent Document 4 discloses a “fixing roller having an elastic layer coated on the surface side of a core metal member and an intermediate layer having higher elasticity than the elastic layer coated on the surface side of the elastic layer”. Has been.

JP 2001-228736 A JP 2004-61873 A JP 2006-267436 A JP 2006-84981 A

  The subject of this invention is providing the fixing member which suppresses generation | occurrence | production of the wrinkle of a surface layer.

The above problem is solved by the following means. That is,
The invention according to claim 1
A substrate;
A first elastic layer provided on a substrate;
The first is provided on the elastic layer, provided on the second elastic layer and the second elastic layer of low elastic modulus Ei than the elastic modulus Ee of the first elastic layer, met thickness following surface layer 20μm A surface layer made of a tubular material coated on the outer peripheral surface of the second elastic layer ,
A fixing member.

The invention according to claim 2
The fixing member according to claim 1, wherein the surface layer includes a fluororesin.

The invention according to claim 3
The fixing member according to claim 1, wherein the second elastic layer includes silicone rubber.

The invention according to claim 4
The fixing member according to claim 1, wherein the fixing member has a belt shape.

The invention according to claim 5
A first rotating body, and a second rotating body arranged in contact with the outer surface of the first rotating body,
The fixing device according to claim 1, wherein at least one of the first rotating body and the second rotating body is the fixing member according to claim 1.

The invention according to claim 6
An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming a latent image on the surface of the charged image carrier;
Developing means for developing the latent image with toner to form a toner image;
Transfer means for transferring the toner image to a recording medium;
Fixing means for fixing the toner image to the recording medium, the fixing means being the fixing device according to claim 5;
An image forming apparatus comprising:

According to the first aspect of the present invention, there is provided a fixing member that suppresses the generation of wrinkles on the surface layer as compared with the case where the elastic modulus Ei of the second elastic layer is higher than the elastic modulus Ee of the first elastic layer.
According to the second aspect of the present invention, the surface layer including the fluororesin that is likely to generate wrinkles as compared with the case where the elastic modulus Ei of the second elastic layer is higher than the elastic modulus Ee of the first elastic layer. Even if the fixing member is provided, a fixing member that suppresses generation of wrinkles on the surface layer is provided.
According to the third aspect of the present invention, there is provided a fixing member that suppresses the generation of wrinkles on the surface layer as compared with the case where the second elastic layer including an elastic material other than silicone rubber is provided.
According to the fourth aspect of the invention, even if the belt-like fixing member is easily wrinkled as compared with the case where the elastic modulus Ei of the second elastic layer is higher than the elastic modulus Ee of the first elastic layer, A fixing member that suppresses generation of wrinkles in the layer is provided.

  According to the inventions according to claims 5 and 6, the second elastic layer has an elastic modulus Ei higher than the elastic modulus Ee of the first elastic layer. A fixing device and an image forming apparatus that suppress image defects are provided.

It is a schematic cross-sectional view showing an example of a fixing member according to the present embodiment. 1 is a schematic configuration diagram illustrating an example of a fixing device according to a first embodiment. It is a schematic block diagram which shows an example of the fixing device which concerns on 2nd Embodiment. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment.

Embodiments that are examples of the present invention will be described below.
In addition, the same code | symbol is provided to the member which has the substantially same function throughout all the drawings, and the overlapping description may be abbreviate | omitted suitably.

[Fixing member]
The fixing member according to this embodiment will be described.
FIG. 1 is a schematic cross-sectional view showing an example of a fixing member according to the present embodiment.

As shown in FIG. 1, the fixing member 110 according to the present embodiment includes, for example, a base 110A, a first elastic layer 110B provided on the base 110A, and a first elastic layer 110B provided on the first elastic layer 110B. 110C of 2 elastic layers and 110D of surface layers provided on the 2nd elastic layer 110C.
The thickness of the surface layer 110D is 20 μm or less. The elastic modulus Ei of the second elastic layer 110C is lower than the elastic modulus Ee of the first elastic layer 110B.

  Note that the fixing member 110 according to the present embodiment is not limited to the above-described layer configuration, and for example, a layer in which a metal layer or a protective layer thereof is interposed between the base 110A and the first elastic layer 110B as necessary. It may be a configuration.

  Here, conventionally, in the fixing member, the surface layer and the elastic layer (the layer located in the first elastic layer 110B of the present embodiment) are used for the purpose of suppressing the generation of wrinkles of the surface layer that causes image defects and the like. A technique is known in which an intermediate layer (a layer located in the second elastic layer 110C of the present embodiment) having a higher elastic modulus than the elastic layer is provided therebetween.

  However, if the elastic modulus of the intermediate layer is made higher than that of the lower elastic layer, the surface layer is reduced to a thickness of 20 μm or less to realize energy saving and high image quality. Has been found to tend to occur. This is because it is difficult to maintain the strength of the thinned surface layer, and if the intermediate layer located between the surface layer and the elastic layer is a layer having a higher elastic modulus than the lower elastic layer, the surface layer is distorted. This is considered to be because the distortion is concentrated on the surface layer.

On the other hand, in the fixing member 110 according to the present embodiment, the elastic modulus Ei of the second elastic layer 110C interposed between the surface layer 110D thinned to 20 μm or less and the first elastic layer 110B is set to the first elastic layer. By making it lower than the elastic modulus Ee of 110B, generation of wrinkles in the surface layer is suppressed.
This is because the second elastic layer 110C positioned between the surface layer 110D and the first elastic layer 110B is a layer having a higher elastic modulus than the lower first elastic layer 110B, thereby generating distortion in the surface layer. In this case, it is considered that the strain does not concentrate only on the surface layer but is dispersed in the first elastic layer 110B together with the second elastic layer 110C as the lower layer.

  Here, the elastic modulus Ei of the second elastic layer 110C is lower than the elastic modulus Ee of the first elastic layer 110B. From the viewpoint of suppressing wrinkles of the surface layer, specifically, the elastic modulus Ei of the second elastic layer 110C. And the elastic modulus Ee of the first elastic layer 110B (elastic modulus Ee−elastic modulus Ei) is, for example, preferably 0.1 MPa or more and 3 MPa or less, preferably 0.3 MPa or more and 2 MPa or less, more preferably It is 0.5 MPa or more and 1 MPa or less.

The elastic modulus Ee of the first elastic layer 110B is, for example, preferably 0.2 MPa or more and 2.5 MPa or less, desirably 0.4 MPa or more and 2.2 MPa or less, more desirably 0.6 MPa or more and 2 MPa or less. is there.
On the other hand, the elastic modulus Ei of the second elastic layer 110C may be, for example, 0.1 MPa or more and 2.2 MPa or less, desirably 0.2 MPa or more and 1.9 MPa or less, more desirably 0.3 MPa or more and 1.7 MPa. It is as follows.

  Note that the elastic modulus of each elastic layer is adjusted by the type of elastic material, its curing density, the type of filler, the amount of addition, and the like.

The elastic modulus of each elastic layer is determined as follows.
First, a sample of the elastic layer to be measured is taken from the fixing member and used as a measurement sample (sample width: 2 mm, sample length: 10 mm).
Using this measurement sample, the elastic modulus is measured by a dynamic viscoelasticity tester RHEOVIBRON (manufactured by ORIENTEC) under measurement conditions of a temperature of 30 ° C., a frequency of 10 Hz and an amplitude of 100 μm.

  Hereinafter, components of the fixing member 110 according to the present embodiment will be described in detail. Note that the reference numerals are omitted.

(Fixing member shape)
The fixing member according to the present embodiment may be in a roll shape or a belt shape. However, the fixing member according to the present embodiment is advantageous in that wrinkles of the surface layer are suppressed even if the surface layer is easily distorted and has a belt shape in which wrinkles are easily generated.

(Base material)
When the fixing member is in a roll shape, examples of the base material include a cylindrical body made of metal (aluminum, SUS, iron, copper, etc.), an alloy, ceramics, FRM (fiber reinforced metal), and the like.
When the fixing member is roll-shaped, the outer diameter and thickness of the base material are preferably, for example, 10 mm to 50 mm in outer diameter. For example, in the case of aluminum, the thickness is 0.5 mm to 4 mm, and SUS ( In the case of stainless steel) or iron, the thickness is 0.1 mm or more and 2 mm or less.

On the other hand, when the fixing member is belt-shaped, examples of the base material include a metal belt (for example, a metal belt such as nickel, aluminum, and stainless steel), a resin belt (for example, polyimide, polyamideimide, polyphenylene sulfide, polyetheretherketone, polyether). Resin belts such as benzimidazole).
The volume resistivity may be controlled by adding and dispersing conductive powder or the like to the resin belt. Specifically, examples of the resin belt include a polyimide belt in which volume resistivity is controlled by adding and dispersing carbon black. Moreover, as a resin belt, what combined the both ends of the elongate polyimide sheet on the puzzle, thermocompression-bonded using the thermocompression-bonding member, and prepared the belt shape is mentioned, for example.

  When the fixing member is belt-shaped, the thickness of the base material is, for example, preferably 20 μm or more and 200 μm or less, desirably 30 μm or more and 150 μm or less, and more desirably 40 μm or more and 130 μm or less.

(First elastic layer)
The first elastic layer includes a heat resistant elastic material. Examples of the heat resistant elastic material include silicone rubber and fluoro rubber.
Examples of the silicone rubber include RTV silicone rubber, HTV silicone rubber, and liquid silicone rubber. Specifically, polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl phenyl silicone rubber (PMQ). ), Fluorosilicone rubber (FVMQ) and the like.
Examples of the fluororubber include vinylidene fluoride rubber, tetrafluoroethylene / propylene rubber, tetrafluoroethylene / perfluoromethyl vinyl ether rubber, phosphazene rubber, and fluoropolyether.
Note that “heat resistance” means a characteristic that does not melt or decompose even when the temperature rises (for example, the fixing temperature) of the fixing device. The same applies hereinafter.

  Various additives may be blended in the first elastic layer. Examples of additives include reinforcing agents (carbon black, etc.), fillers (calcium carbonate, etc.), softeners (paraffins, etc.), processing aids (stearic acid, etc.), anti-aging agents (amines, etc.), additives Examples include sulfurizing agents (sulfur, metal oxides, peroxides, etc.), functional fillers (alumina, etc.), and the like.

Here, from the viewpoint of suppressing wrinkles on the surface layer, as a suitable configuration of the first elastic layer, for example,
1) Configuration including silicone rubber, 2) Configuration including fluoro rubber, and the like.

  The thickness of the first elastic layer is, for example, preferably from 30 μm to 600 μm, and preferably from 100 μm to 500 μm.

(Second elastic layer)
The second elastic layer is also configured to include a heat resistant elastic material. Examples of the heat resistant elastic material include silicone rubber and fluoro rubber. Examples of these silicone rubber and fluororubber are the same as those described for the first elastic layer.
Moreover, various additives may be mix | blended with the 2nd elastic layer similarly to the 1st elastic layer.

Here, from the viewpoint of suppressing wrinkles on the surface layer, as a suitable configuration of the second elastic layer, for example,
1) Configuration including silicone rubber, 2) Configuration including fluoro rubber, and the like.
In particular, the second elastic layer includes silicone rubber (for example, dimethylpolysiloxane rubber), so that wrinkles on the surface layer are easily suppressed.

  The thickness of the second elastic layer is, for example, preferably 5 μm or more and 50 μm or less, and desirably 10 μm or more and 30 μm or less.

(Surface layer)
The surface layer includes, for example, a heat resistant release material.
Examples of the heat-resistant release material include fluororubber, fluororesin, silicone resin, and polyimide resin.
Among these, a fluororesin is preferable as the heat-resistant release material. The surface layer containing the fluororesin is likely to be wrinkled when it is thinned, but in this embodiment, the wrinkle of the surface layer is suppressed.
Specific examples of such a fluororesin include, for example, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), Examples thereof include polyethylene / tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychloroethylene trifluoride (PCTFE), and vinyl fluoride (PVF).

  The thickness of the surface layer is 20 μm or less, but may be, for example, 5 μm or more and 20 μm or less, and desirably 10 μm or more and 20 μm or less.

(Use of fixing member)
The fixing member according to the present embodiment is applied to both a heating belt and a pressure belt, for example. The heating belt may be either a heating belt that is heated by an electromagnetic induction method or a heating belt that is heated from an external heat source.
However, when the fixing member according to the present embodiment is applied to a heating belt that is heated by an electromagnetic induction method, a metal layer (heat generation layer) that generates heat by electromagnetic induction may be provided between the base material and the first elastic layer. Good.

[Fixing device]
The fixing device according to the present embodiment has various configurations, and includes, for example, a first rotating body and a second rotating body disposed in contact with the outer surface of the first rotating body. The fixing member according to the present embodiment is applied as at least one of the first rotating body and the second rotating body.

Hereinafter, a fixing device including a heating belt and a pressure roll will be described as first and second embodiments. In the first and second embodiments, the fixing member according to this embodiment can be applied to either a heating belt or a pressure roll.
The fixing device according to this embodiment is not limited to the first and second embodiments, and may be a fixing device including a heating roll or a heating belt and a pressure belt. The fixing member according to the present embodiment can be applied to any of a heating roll, a heating belt, and a pressure belt.
The fixing device according to the present embodiment is not limited to the first and second embodiments, and may be an electromagnetic induction heating type fixing device.

(First Embodiment of Fixing Device)
The fixing device according to the first embodiment will be described. FIG. 2 is a schematic schematic diagram illustrating an example of the fixing device according to the first embodiment.

As illustrated in FIG. 2, the fixing device 60 according to the first embodiment includes, for example, a heating roll 61 (an example of a first rotating body) that is rotationally driven, a pressure belt 62 (an example of a second rotating body), A pressing pad 64 (an example of a pressing member) that presses the heating roll 61 via the pressure belt 62 is provided.
In addition, the press pad 64 should just pressurize the pressurization belt 62 and the heating roll 61 relatively, for example. Therefore, the pressure belt 62 side may be pressed by the heating roll 61, and the heating roll 61 side may be pressed by the heating roll 61.

  Inside the heating roll 61, a halogen lamp 66 (an example of a heating means) is disposed. The heating means is not limited to the halogen lamp, and other heat generating members that generate heat may be used.

  On the other hand, for example, a temperature sensitive element 69 is disposed on the surface of the heating roll 61 in contact therewith. The lighting of the halogen lamp 66 is controlled based on the temperature measurement value by the temperature sensing element 69, and the surface temperature of the heating roll 61 is maintained at a target set temperature (for example, 150 ° C.).

  The pressure belt 62 is rotatably supported by, for example, a pressing pad 64 and a belt traveling guide 63 disposed inside. And it is pressed against the heating roll 61 by the pressing pad 64 in the sandwiching area N (nip part).

For example, the pressing pad 64 is disposed inside the pressure belt 62 in a state of being pressed against the heating roll 61 via the pressure belt 62, and forms a sandwiching region N with the heating roll 61. Yes.
For example, the pressing pad 64 is provided with a front clamping member 64a for securing a wide clamping area N on the entrance side of the clamping area N, and a peeling clamping member 64b for distorting the heating roll 61. Is arranged on the exit side of the sandwiching region N.

In order to reduce the sliding resistance between the inner peripheral surface of the pressure belt 62 and the pressing pad 64, for example, the sheet-like sliding on the surface of the front sandwiching member 64a and the peeling sandwiching member 64b in contact with the pressure belt 62 A member 68 is provided. The pressing pad 64 and the sliding member 68 are held by a metal holding member 65.
The sliding member 68 is provided, for example, so that its sliding surface is in contact with the inner peripheral surface of the pressure belt 62, and is involved in holding and supplying oil existing between the sliding member 68 and the pressure belt 62. .

  For example, a belt traveling guide 63 is attached to the holding member 65 so that the pressure belt 62 rotates.

  For example, the heating roll 61 is rotated in the arrow S direction by a drive motor (not shown), and the pressure belt 62 is rotated in the arrow R direction opposite to the rotation direction of the heating roll 61 following the rotation. That is, for example, while the heating roll 61 rotates in the clockwise direction in FIG. 2, the pressure belt 62 rotates in the counterclockwise direction.

  Then, the sheet K (an example of a recording medium) having an unfixed toner image is guided by, for example, the fixing inlet guide 56 and conveyed to the sandwiching area N. When the paper K passes through the sandwiching area N, the toner image on the paper K is fixed by pressure and heat acting on the sandwiching area N.

  In the fixing device 60 according to the first embodiment, for example, the concave sandwiched front sandwiching member 64a that follows the outer peripheral surface of the heating roll 61 has a wider sandwiched region N as compared to the configuration without the front sandwiching member 64a. Secured.

  Further, in the fixing device 60 according to the first embodiment, for example, by disposing the peeling sandwiching member 64 b so as to protrude from the outer peripheral surface of the heating roll 61, the heating roll 61 is distorted in the exit region of the sandwiching region N. Is configured to be locally large.

  If the peeling and clamping member 64b is arranged in this way, for example, the sheet K after being fixed passes through the locally formed distortion when passing through the peeling and clamping area. Is easy to peel from the heating roll 61.

  As an auxiliary means for peeling, for example, a peeling member 70 is disposed on the downstream side of the sandwiching area N of the heating roll 61. For example, the peeling member 70 is held by the holding member 72 in a state in which the peeling claw 71 is close to the heating roll 61 in a direction (counter direction) opposite to the rotation direction of the heating roll 61.

(Second Embodiment of Fixing Device)
A fixing device according to the second embodiment will be described. FIG. 3 is a schematic diagram illustrating an example of a fixing device according to the second embodiment.

  As shown in FIG. 3, the fixing device 80 according to the first embodiment, for example, presses the fixing belt module 86 including the heating belt 84 (an example of the first rotating body) and the heating belt 84 (the fixing belt module 86). And a pressurizing roll 88 (an example of a second rotating body) arranged. For example, a sandwiching region N (nip portion) where the heating belt 84 (fixing belt module 86) and the pressure roll 88 come into contact is formed. In the sandwiching area N, the sheet K (an example of a recording medium) is pressurized and heated to fix the toner image.

The fixing belt module 86 includes, for example, an endless heating belt 84 and a heating belt 84 wound around the pressure roll 88. The fixing belt module 86 is driven to rotate by a rotational force of a motor (not shown) and the heating belt 84 has an inner circumference. A heating and pressing roll 89 that is pressed from the surface toward the pressing roll 88 and a support roll 90 that supports the heating belt 84 from the inside at a position different from the heating and pressing roll 89 are provided.
The fixing belt module 86 is, for example, a support roll 92 that is disposed outside the heating belt 84 and defines a circulation path thereof, and a posture correction roll 94 that corrects the posture of the heating belt 84 from the heating pressure roll 89 to the support roll 90. And a support roll 98 for applying tension to the heating belt 84 from the inner peripheral surface on the downstream side of the sandwiching area N, which is an area where the heating belt 84 (fixing belt module 86) and the pressure roll 88 are in contact with each other. ing.

The fixing belt module 86 is provided, for example, such that a sheet-like sliding member 82 is interposed between the heating belt 84 and the heating press roll 89.
The sliding member 82 is provided, for example, so that its sliding surface is in contact with the inner peripheral surface of the heating belt 84, and is involved in holding and supplying oil existing between the sliding member 82 and the heating belt 84.
Here, the sliding member 82 is provided, for example, in a state in which both ends thereof are supported by the support member 96.

  Inside the heating and pressing roll 89, for example, a halogen heater 89A (an example of heating means) is provided.

The support roll 90 is, for example, a cylindrical roll formed of aluminum, and a halogen heater 90A (an example of a heating unit) is disposed therein so that the heating belt 84 is heated from the inner peripheral surface side. It has become.
For example, spring members (not shown) that press the heating belt 84 outward are disposed at both ends of the support roll 90.

The support roll 92 is, for example, a cylindrical roll made of aluminum, and a release layer made of a fluororesin having a thickness of 20 μm is formed on the surface of the support roll 92.
The release layer of the support roll 92 is formed, for example, to prevent toner and paper powder from the outer peripheral surface of the heating belt 84 from accumulating on the support roll 92.
For example, a halogen heater 92A (an example of a heating source) is disposed inside the support roll 92, and the heating belt 84 is heated from the outer peripheral surface side.

  That is, for example, the heating belt 84 is heated by the heating press roll 89, the support roll 90, and the support roll 92.

The posture correction roll 94 is, for example, a cylindrical roll formed of aluminum, and an end position measuring mechanism (not shown) that measures the end position of the heating belt 84 is disposed in the vicinity of the posture correction roll 94. ing.
For example, the posture correcting roll 94 is provided with an axial displacement mechanism (not shown) that displaces the contact position in the axial direction of the heating belt 84 in accordance with the measurement result of the end position measuring mechanism. Configured to control.

  On the other hand, for example, the pressure roll 88 is rotatably supported, and is provided by being pressed against a portion where the heating belt 84 is wound around the heating press roll 89 by an urging means such as a spring (not shown). Thus, as the heating belt 84 (heating press roll 89) of the fixing belt module 86 rotates in the direction of arrow S, the pressing roll 88 is moved by the arrow R following the heating belt 84 (heating press roll 89). It is designed to rotate in the direction.

  Then, the sheet K having the unfixed toner image (not shown) is conveyed in the direction of the arrow P, and when guided to the sandwiching area N of the fixing device 80, it is fixed by the pressure and heat acting on the sandwiching area N. The

  In the fixing device 80 according to the second embodiment, the embodiment in which the halogen heater (halogen lamp) is applied as an example of the heating source has been described. However, the present invention is not limited to this. Etc.), resistance heating elements (heating elements that generate Joule heat by passing a current through the resistance: for example, a film having a thick film resistance formed on a ceramic substrate and fired) May be.

[Image forming apparatus]
Next, the image forming apparatus according to the present embodiment will be described.
The image forming apparatus of the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, a latent image forming unit that forms a latent image on the surface of the charged image carrier, and the latent image as a toner. Developing means for forming a toner image by developing, a transfer means for transferring the toner image to a recording medium, and a fixing means for fixing the toner image to the recording medium. The fixing device according to this embodiment is applied as the fixing unit.

The image forming apparatus according to the present embodiment will be described below with reference to the drawings.
FIG. 5 is a schematic configuration diagram showing the configuration of the image forming apparatus according to the present embodiment.

  As shown in FIG. 5, the image forming apparatus 100 according to the present embodiment is, for example, an intermediate transfer type image forming apparatus generally called a tandem type, and a plurality of toner images of each color component are formed by an electrophotographic system. Image forming units 1Y, 1M, 1C, and 1K, and a primary transfer unit 10 that sequentially transfers (primary transfer) the color component toner images formed by the image forming units 1Y, 1M, 1C, and 1K to the intermediate transfer belt 15. The secondary transfer unit 20 that collectively transfers (secondary transfer) the superimposed toner image transferred onto the intermediate transfer belt 15 onto the paper K that is a recording medium, and the fixing that fixes the secondary transferred image onto the paper K. Device 60. Further, the image forming apparatus 100 includes a control unit 40 that controls the operation of each device (each unit).

  This fixing device 60 is the fixing device 60 according to the first embodiment described above. Note that the image forming apparatus 100 may include the fixing device 80 according to the second embodiment described above.

  Each of the image forming units 1Y, 1M, 1C, and 1K of the image forming apparatus 100 includes a photoconductor 11 that rotates in the arrow A direction as an example of an image holding body that holds a toner image formed on the surface.

  A charger 12 for charging the photoconductor 11 is provided around the photoconductor 11 as an example of a charging unit, and a laser exposure device for writing an electrostatic latent image on the photoconductor 11 as an example of a latent image forming unit. 13 (the exposure beam is indicated by Bm in the figure) is provided.

  Further, around the photosensitive member 11, as an example of a developing unit, a developing device 14 that accommodates each color component toner and visualizes the electrostatic latent image on the photosensitive member 11 with the toner is provided. A primary transfer roll 16 for transferring the color component toner images formed thereon onto the intermediate transfer belt 15 by the primary transfer unit 10 is provided.

  Further, a photoconductor cleaner 17 for removing residual toner on the photoconductor 11 is provided around the photoconductor 11, and a charger 12, a laser exposure device 13, a developing device 14, a primary transfer roll 16, and a photoconductor cleaner. Seventeen electrophotographic devices are sequentially arranged along the rotation direction of the photoconductor 11. These image forming units 1Y, 1M, 1C, and 1K are arranged substantially linearly in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side of the intermediate transfer belt 15. Has been.

The intermediate transfer belt 15 as an intermediate transfer member is formed of a film-like pressure belt containing a resin such as polyimide or polyamide as a base layer and containing an appropriate amount of an antistatic agent such as carbon black. The volume resistivity is 10 ⁶ Ωcm or more and 10 ¹⁴ Ωcm or less, and the thickness is, for example, about 0.1 mm.

  The intermediate transfer belt 15 is circulated and driven (rotated) at a predetermined speed in the direction B shown in FIG. 5 by various rolls. As these various rolls, a drive roll 31 that is driven by a motor (not shown) having excellent constant speed to rotate the intermediate transfer belt 15, and an intermediate transfer belt that extends substantially linearly along the arrangement direction of the photoreceptors 11. 15, a support roll 32 that supports the intermediate transfer belt 15, a tension applying roll 33 that functions as a correction roll that applies a constant tension to the intermediate transfer belt 15 and prevents the intermediate transfer belt 15 from meandering, and a back roll provided in the secondary transfer unit 20. 25. A cleaning back roll 34 is provided in a cleaning unit that scrapes off residual toner on the intermediate transfer belt 15.

The primary transfer unit 10 includes a primary transfer roll 16 that is disposed to face the photoconductor 11 with the intermediate transfer belt 15 interposed therebetween. The primary transfer roll 16 includes a shaft and a sponge layer as an elastic layer fixed around the shaft. The shaft is a cylindrical bar made of metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a blend rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less.

  The primary transfer roll 16 is placed in pressure contact with the photoreceptor 11 with the intermediate transfer belt 15 in between. Further, the primary transfer roll 16 has a voltage (primary polarity) opposite to the toner charging polarity (negative polarity; the same applies hereinafter). Transfer bias) is applied. As a result, the toner images on the respective photoconductors 11 are sequentially electrostatically attracted to the intermediate transfer belt 15 so that the superimposed toner images are formed on the intermediate transfer belt 15.

  The secondary transfer unit 20 includes a back roll 25 and a secondary transfer roll 22 disposed on the toner image holding surface side of the intermediate transfer belt 15.

The back roll 25 is made of a tube of EPDM and NBR blend rubber with carbon dispersed on the surface, and the inside is made of EPDM rubber. And it is formed so that the surface resistivity may be 10 ⁷ Ω / □ or more and 10 ¹⁰ Ω / □ or less, and the hardness is set to, for example, 70 ° (Asker C: manufactured by Kobunshi Keiki Co., Ltd., the same shall apply hereinafter). The The back roll 25 is disposed on the back side of the intermediate transfer belt 15 to constitute a counter electrode of the secondary transfer roll 22, and a metal power supply roll 26 to which a secondary transfer bias is stably applied is disposed in contact. ing.

On the other hand, the secondary transfer roll 22 includes a shaft and a sponge layer as an elastic layer fixed around the shaft. The shaft is a cylindrical bar made of metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a blend rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less.

  The secondary transfer roll 22 is placed in pressure contact with the back roll 25 with the intermediate transfer belt 15 interposed therebetween. Further, the secondary transfer roll 22 is grounded and a secondary transfer bias is formed between the secondary transfer roll 22 and the back roll 25, and the secondary transfer roll 22 is grounded. The toner image is secondarily transferred onto the paper K conveyed to the transfer unit 20.

  Further, on the downstream side of the secondary transfer portion 20 of the intermediate transfer belt 15, an intermediate transfer belt that removes residual toner and paper dust on the intermediate transfer belt 15 after the secondary transfer and cleans the surface of the intermediate transfer belt 15. A cleaner 35 is provided so as to be able to contact and separate.

  The intermediate transfer belt 15, the primary transfer unit 10 (primary transfer roll 16), and the secondary transfer unit 20 (secondary transfer roll 22) correspond to an example of a transfer unit.

  On the other hand, on the upstream side of the yellow image forming unit 1Y, a reference sensor (home position sensor) 42 that generates a reference signal serving as a reference for taking image forming timings in the image forming units 1Y, 1M, 1C, and 1K. It is arranged. Further, an image density sensor 43 for adjusting image quality is disposed on the downstream side of the black image forming unit 1K. The reference sensor 42 recognizes a mark provided on the back side of the intermediate transfer belt 15 and generates a reference signal. In response to an instruction from the control unit 40 based on the recognition of the reference signal, each image forming unit 1Y, 1M, 1C, and 1K are configured to start image formation.

  Further, in the image forming apparatus according to the present embodiment, as a transport unit that transports the paper K, the paper storage unit 50 that stores the paper K, and the paper K accumulated in the paper storage unit 50 is taken out at a predetermined timing. A paper feed roll 51 that transports the paper K, a transport roll 52 that transports the paper K fed by the paper feed roll 51, a transport guide 53 that feeds the paper K transported by the transport roll 52 to the secondary transfer unit 20, and a secondary transfer A conveyance belt 55 that conveys the sheet K conveyed after the secondary transfer by the roll 22 to the fixing device 60 and a fixing entrance guide 56 that guides the sheet K to the fixing device 60 are provided.

Next, a basic image forming process of the image forming apparatus according to the present embodiment will be described.
In the image forming apparatus according to the present embodiment, image data output from an image reading device (not shown) or a personal computer (PC) (not shown) is subjected to image processing by an image processing device (not shown), and then the image forming unit 1Y. , 1M, 1C, 1K, image forming work is executed.

  In the image processing apparatus, image processing such as shading correction, positional deviation correction, brightness / color space conversion, gamma correction, frame deletion, color editing, moving editing, and other image editing is performed on the input reflectance data. Applied. The image data that has been subjected to image processing is converted into color material gradation data of four colors Y, M, C, and K, and is output to the laser exposure unit 13.

  The laser exposure unit 13 irradiates each of the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K with, for example, an exposure beam Bm emitted from a semiconductor laser in accordance with the input color material gradation data. . In each of the photoreceptors 11 of the image forming units 1Y, 1M, 1C, and 1K, the surface is charged by the charger 12, and then the surface is scanned and exposed by the laser exposure unit 13 to form an electrostatic latent image. The formed electrostatic latent images are developed as toner images of respective colors Y, M, C, and K by the respective image forming units 1Y, 1M, 1C, and 1K.

  The toner images formed on the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K are transferred onto the intermediate transfer belt 15 in the primary transfer unit 10 where the photoconductors 11 and the intermediate transfer belt 15 are in contact with each other. The More specifically, in the primary transfer portion 10, a voltage (primary transfer bias) having a polarity opposite to the toner charging polarity (minus polarity) is applied to the base material of the intermediate transfer belt 15 by the primary transfer roll 16, and the toner image. Are sequentially superimposed on the surface of the intermediate transfer belt 15 to perform primary transfer.

  After the toner images are sequentially primary transferred onto the surface of the intermediate transfer belt 15, the intermediate transfer belt 15 moves and the toner image is conveyed to the secondary transfer unit 20. When the toner image is conveyed to the secondary transfer unit 20, the conveyance unit rotates the paper feed roll 51 in accordance with the timing at which the toner image is conveyed to the secondary transfer unit 20. A sheet K of a predetermined size is supplied. The paper K supplied by the paper feed roll 51 is transported by the transport roll 52, and reaches the secondary transfer unit 20 through the transport guide 53. Before reaching the secondary transfer unit 20, the sheet K is temporarily stopped, and the registration roll (not shown) rotates in accordance with the movement timing of the intermediate transfer belt 15 on which the toner image is held. And the position of the toner image are aligned.

  In the secondary transfer unit 20, the secondary transfer roll 22 is pressed against the back roll 25 via the intermediate transfer belt 15. At this time, the sheet K conveyed at the same timing is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. At this time, when a voltage (secondary transfer bias) having the same polarity as the toner charging polarity (negative polarity) is applied from the power supply roll 26, a transfer electric field is formed between the secondary transfer roll 22 and the back roll 25. Is done. The unfixed toner image held on the intermediate transfer belt 15 is collectively electrostatically transferred onto the paper K in the secondary transfer unit 20 pressed by the secondary transfer roll 22 and the back roll 25. The

  Thereafter, the sheet K on which the toner image has been electrostatically transferred is conveyed as it is while being peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22, and is conveyed downstream of the secondary transfer roll 22 in the sheet conveyance direction. It is conveyed to the belt 55. The transport belt 55 transports the paper K to the fixing device 60 in accordance with the optimal transport speed in the fixing device 60. The unfixed toner image on the paper K conveyed to the fixing device 60 is fixed on the paper K by receiving a fixing process with heat and pressure by the fixing device 60. Then, the sheet K on which the fixed image is formed is conveyed to a paper discharge container (not shown) provided in the discharge unit of the image forming apparatus.

  On the other hand, after the transfer to the paper K is completed, the residual toner remaining on the intermediate transfer belt 15 is conveyed to the cleaning unit as the intermediate transfer belt 15 rotates, and is cleaned by the cleaning back roll 34 and the intermediate transfer belt cleaner 35. It is removed from the intermediate transfer belt 15.

  Although the embodiments of the present invention have been described above, the present invention is not construed as being limited to the above-described embodiments, and various modifications, changes, and improvements can be made, and a range that satisfies the requirements of the present invention. Needless to say, this is feasible.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

[Example 1]
-Fabrication of substrate-
A polyamic acid solution having a solid content concentration of 18% using NMP (N-methylpyrrolidone) as a solvent is prepared. A coating film was formed and dried by heating at 145 ° C. for 30 minutes to obtain a dried film. Remove the dried film from the centrifugal mold and set it in an imidized mold. Heat at 200 ° C for 20 minutes and 380 ° C for 20 minutes to obtain an endless belt-shaped polyimide (PI) base material with an inner diameter of 168 mm and a film thickness of 80 µm. It was.

-Formation of the first elastic layer-
Next, a liquid silicone rubber “DY35-2147 (manufactured by Toray Dow Corning)” was applied onto the prepared PI substrate with a blade, heated at 110 ° C. for 20 minutes, then heated at 200 ° C. for 4 hours, and a film thickness of 200 μm. The first elastic layer was formed.

-Formation of the second elastic layer-
Next, a liquid silicone rubber “DY35-1306 (manufactured by Toray Dow Corning)” was applied onto the formed first elastic layer with a blade and heated at 60 ° C. for 30 minutes to form a second elastic layer having a thickness of 20 μm. .

-Formation of surface layer-
Next, a PFA tube having a film thickness of 20 μm, which is 2% smaller than the outer diameter of the polyimide base material formed up to the second elastic layer, is prepared, and the outer mold whose inner diameter is% larger than the outer diameter of the polyimide base material. A PFA tube was set on the inner periphery. Then, with the polyimide base material formed up to the second elastic layer inserted inside the PFA tube, the PFA tube is removed from the outer mold and coated on the outer periphery of the second elastic layer, heated at 200 ° C. for 30 minutes, A surface layer having a thickness of 20 μm was formed.

  Through the above steps, a fixing belt was produced.

[Examples 2 to 8, Comparative Examples 1 to 9]
A fixing belt was produced in the same manner as in Example 1 except that the composition, heat treatment and thickness of the first and second elastic layers, and the composition and thickness of the surface layer were changed according to Table 1.

[Evaluation]
(Evaluation of the physical properties)
The elastic modulus of each elastic layer of the fixing belt obtained in each example was measured according to the method described. The results are shown in Table 1.

(Actual machine evaluation)
As the heating belt, the fixing belt obtained in each example was mounted with a fixing device for Color 1000 Pres manufactured by Fuji Xerox Co., Ltd.
Next, the fixing device equipped with the fixing belt was incorporated in Fuji Xerox Co., Ltd .: Color 1000 Press.
Then, the following evaluation was performed using this image forming apparatus.

-Evaluation of wrinkle generation on the surface layer of the fixing belt-
A half-tone fixed image with an image density of 30% is output continuously by the image forming device, and the time until the wrinkles are visually observed on the surface layer of the fixing belt, or the degree of the wrinkles generated is evaluated. did. However, this evaluation was performed with reference to a reference fixing belt manufactured in the same manner as in Example 1 except that the second elastic layer was not formed.
The evaluation criteria are as follows.
A: Compared with the reference fixing belt, the time until the generation of the surface layer wrinkles is 2.1 times or longer.
B: Compared with the reference fixing belt, the time until the generation of the surface layer wrinkles increased from 1.6 times to 2.0 times.
C: Compared with the reference fixing belt, the time until the generation of the surface layer wrinkles was 1.1 times to 1.5 times.
D: The time until the generation of the surface layer wrinkles was not changed or shortened as compared with the reference fixing belt.

  From the above results, it can be seen that in this example, better results were obtained with respect to the evaluation of wrinkles on the surface layer of the fixing belt than in the comparative example.

Details of the abbreviations in Table 1 are as follows.
DY35-2147: Liquid silicone rubber “DY35-2147 (manufactured by Toray Dow Corning)”
DY35-1306: Liquid silicone rubber “DY35-1306 (manufactured by Toray Dow Corning)”
KE-1820: Liquid silicone rubber “KE-1820 (manufactured by Shin-Etsu Chemical Co., Ltd.)”
KE-1830: Liquid silicone rubber “KE-1830 (manufactured by Shin-Etsu Chemical Co., Ltd.)”
KE-1833: Liquid silicone rubber “KE-1833 (manufactured by Shin-Etsu Chemical Co., Ltd.)”
KE-2019-40A / B: Liquid silicone rubber “KE-2019-40A / B (manufactured by Shin-Etsu Chemical Co., Ltd.)”

60 fixing device 62 heating belt 64 pressure roller 66 pressing pad 68 support member 70 electromagnetic induction coil 72 coil support member 80 fixing device 82 sliding member 84 heating belt 86 fixing belt module 88 pressure roll 89A halogen heater 89 heating pressure roll 90A Halogen heater 90 Support roll 92A Halogen heater 92 Support roll 94 Posture correction roll 96 Support member 98 Support roll 100 Image forming apparatus 110 Fixing member

Claims (6)

A substrate;
A first elastic layer provided on a substrate;
The first is provided on the elastic layer, provided on the second elastic layer and the second elastic layer of low elastic modulus Ei than the elastic modulus Ee of the first elastic layer, met thickness following surface layer 20μm A surface layer made of a tubular material coated on the outer peripheral surface of the second elastic layer ,
A fixing member.   The fixing member according to claim 1, wherein the surface layer includes a fluororesin.   The fixing member according to claim 1, wherein the second elastic layer includes silicone rubber.   The fixing member according to claim 1, wherein the fixing member has a belt shape. A first rotating body, and a second rotating body arranged in contact with the outer surface of the first rotating body,
The fixing device according to claim 1, wherein at least one of the first rotating body and the second rotating body is the fixing member according to claim 1. An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming a latent image on the surface of the charged image carrier;
Developing means for developing the latent image with toner to form a toner image;
Transfer means for transferring the toner image to a recording medium;
Fixing means for fixing the toner image to the recording medium, the fixing means being the fixing device according to claim 5;
An image forming apparatus comprising: